[shardformer] Align bert value (#3907)

* add bert align test, fix dist loss bug

* forward and backward align

* add ignore index

* add shardformer CI

* add gather_output optional for user in shardconfig

* update readme with optional gather_ouput

* add dist crossentropy loss test, remove unused files

* remove unused file

* remove unused file

* rename the file

* polish code

colossalai/shardformer/shard/shard_config.py

@@ -5,16 +5,14 @@ __all__ = ['ShardConfig']
 
 @dataclass
 class ShardConfig:
-    """
-    The config for sharding the huggingface model for test
+    r"""
+    The config for sharding the huggingface model
+
+    Args:
+        rank (int): The rank of local process
+        world_size (int): The world size of the distributed process
+        gather_output (bool): Whether to gather the output of the model of the last layer
     """
     rank: int
-    fp16: bool = True
-    num_gpus: int = 2
     world_size: int = 2
-    backend = "nccl"
-    verbose: str = 'simple'
-    seed: int = None
-    require_grad: bool = False
-    master_addr: str = "127.0.0.1"
-    master_port: int = 29500
+    gather_output: bool = True